Dinosaurs Almost Had To Answer To Something Else
By the skin of their teeth 200 million years ago, dinosaurs defeated a fierce group of beasts competing for the right to rule the Earth, said scientists Tuesday.
Dinosaurs emerged 230 million years ago, in the Triassic Period, and battled for almost 30 million years with a faction of vicious reptiles called crurotarsans, relatives of contemporary crocodiles that developed into gargantuan sizes and resembled dinosaurs.
For awhile, most scientists supposed dinosaurs were basically more advanced to crurotarsans and survived because the earliest dinosaurs were two-legged, not four, and because they might have been warm-blooded.
"If we were standing around in the late Triassic period 210 million years ago and were asked what group is going to go on and take over the world, I think a reasonable gambler would say the crurotarsans. It’s not that the dinosaurs weren’t doing well. The crurotarsans were doing more," Steve Brusatte said.
But scientists headed up by Steve Brusatte of Columbia University and American Museum of Natural History in New York performed a widespread assessment of fossils and discovered that the two groups were developing at the same speed and the crurotarsans really had a superior range of body types, diets and lifestyles.
The dinosaurs triumphed, Brusatte finished, because some form of planetary mishap 200 million years ago — striking climate change or possibly a great meteorite collision — nearly wiped out the crurotarsans while sparing the dinosaurs.
"The fundamental question is why were the dinosaurs able to become so dominant," Brusatte said. "Evolution on a big scale oftentimes is a matter of luck."
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Image Caption: Not T. rex: Crurotarsan Batrachotomus, a prime example of a crocodile-relative that was very similar to dinosaurs, housed in the Staatlitches Museum fur Naturkunde, Stuttgart, Germany. Credit: S. Brusatte
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